Modbus: Add the ability to specify command_on, command_off for “hvac_onoff_register” in the “climates” configuration instead of using only 1 or 0

This will be useful for anyone with devices that have values other than 0 or 1 for this register. For example for my air conditioner I need to use values 0xAA, 0x55

No first hand experience, here, but a quick look at the doc seems to indicate it’s already possible